scholarly journals Rapid Inactivation of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) by Tungsten Trioxide-Based (WO3) Photocatalysis

2020 ◽  
Author(s):  
Silvia Ghezzi ◽  
Isabel Pagani ◽  
Guido Poli ◽  
Stefano Perboni ◽  
Elisa Vicenzi
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Tungsten Trioxide ◽  
Plaque Assay ◽  
Vero Cells ◽  
Viral Rna ◽  
Indoor Environments ◽  
Viral Plaque ◽  
Droplet Nuclei ◽  
Indoor Conditions ◽  
Respiratory Droplets

AbstractSevere acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the etiological agent of coronavirus disease 2019 (COVID-19), is transmitted person-to-person via respiratory droplets and, likely, via smaller droplet nuclei light enough to remain suspended in the air for hours and contaminate surfaces particularly in indoor conditions. Thus, effective measures are needed to prevent SARS-CoV-2 transmission in indoor environments. In this regard, we have investigated whether a system based on a filter combining Tungsten Trioxide-Based (WO3) photocatalysis and an antiviral fabric treated-copper nanocluster could inactivate SARS-CoV-2. To this purpose, an infectious SARS-CoV-2 suspension was introduced in the upper opening of a closed cylinder containing a WO3 filter and a lightbased system that activates WO3 and the antiviral fabric. From the bottom exit, aliquots of fluid were collected every 10 min (up to 60 min) and tested for their infectivity by means of a viral plaque assay in Vero cells whereas, in parallel, the viral RNA content was measured by quantitative PCR (qPCR). As we have previously shown for SARS-CoV, a 1:1,000 ratio of plaque forming units (PFU) vs. viral RNA copies was observed also for SARS-CoV-2. After 10 min, the infectious viral content was already decreased by 98.2% reaching 100% inactivation after 30 min whereas the SARS-CoV-2 RNA load was decreased of 1.5 log10 after 30 min. Thus, in spite of only a partial decrease of viral RNA, SARS-CoV-2 infectivity was completely abolished by the WO3 photocatalysis system by 30 min. These results support the hypothesis that this system could be exploited to achieve SARS-CoV-2 inactivation in indoor environments.

scholarly journals Inhibition of Severe Acute Respiratory Syndrome Virus Replication by Small Interfering RNAs in Mammalian Cells

2004 ◽  
Vol 78 (14) ◽  
pp. 7523-7527 ◽  
Author(s):  
Zhi Wang ◽  
Lili Ren ◽  
Xingang Zhao ◽  
Tao Hung ◽  
Anming Meng ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Mammalian Cells ◽  
Specific Treatment ◽  
Vero Cells ◽  
Viral Rna ◽  
Respiratory Syndrome Virus ◽  
Small Interfering Rnas ◽  
Protein Levels ◽  
Cytopathic Effects ◽  
Novel Coronavirus

ABSTRACT Severe acute respiratory syndrome (SARS) is an acute respiratory infectious disease that spread worldwide in early 2003. The cause was determined as a novel coronavirus (CoV), SARS-associated CoV (SARS-CoV), with a single-stranded, plus-sense RNA. To date, no effective specific treatment has been identified. To exploit the possibility of using RNA interference as a therapeutic approach to fight the disease, plasmid-mediated small interfering RNAs (siRNAs) were generated to target the SARS-CoV genome. The expression of siRNAs from two plasmids, which specifically target the viral RNA polymerase, effectively blocked the cytopathic effects of SARS-CoV on Vero cells. These two plasmids also inhibited viral replication as shown by titer assays and by an examination of viral RNA and protein levels. Thus, our results demonstrated the feasibility of developing siRNAs as effective anti-SARS drugs.

scholarly journals Decanoyl-Arg-Val-Lys-Arg-Chloromethylketone: An Antiviral Compound That Acts against Flaviviruses through the Inhibition of Furin-Mediated prM Cleavage

Viruses ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1011 ◽  
Author(s):  
Imran ◽  
Saleemi ◽  
Chen ◽  
Wang ◽  
Zhou ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Mammalian Cells ◽  
Plaque Assay ◽  
Virus Titer ◽  
Vero Cells ◽  
Immunofluorescence Assay ◽  
Viral Rna ◽  
Antiviral Compound ◽  
Mosquito Cells ◽  
Infection Treatment

Flaviviruses, such as Zika virus (ZIKV), Japanese encephalitis virus (JEV), Dengue virus (DENV), and West Nile virus (WNV), are important arthropod-borne pathogens that present an immense global health problem. Their unpredictable disease severity, unusual clinical features, and severe neurological manifestations underscore an urgent need for antiviral interventions. Furin, a host proprotein convertase, is a key contender in processing flavivirus prM protein to M protein, turning the inert virus to an infectious particle. For this reason, the current study was planned to evaluate the antiviral activity of decanoyl-Arg-Val-Lys-Arg-chloromethylketone, a specific furin inhibitor, against flaviviruses, including ZIKV and JEV. Analysis of viral proteins revealed a significant increase in the prM/E index of ZIKV or JEV in dec-RVKR-cmk-treated Vero cells compared to DMSO-treated control cells, indicating dec-RVKR-cmk inhibits prM cleavage. Plaque assay, qRT-PCR, and immunofluorescence assay revealed a strong antiviral activity of dec-RVKR-cmk against ZIKV and JEV in terms of the reduction in virus progeny titer and in viral RNA and protein production in both mammalian cells and mosquito cells. Time-of-drug addition assay revealed that the maximum reduction of virus titer was observed in post-infection treatment. Furthermore, our results showed that dec-RVKR-cmk exerts its inhibitory action on the virus release and next round infectivity but not on viral RNA replication. Taken together, our study highlights an interesting antiviral activity of dec-RVKR-cmk against flaviviruses.

scholarly journals Air-Conditioning and the Transmission of COVID-19 in Indoor Environment

2021 ◽  
Vol 10 (3) ◽  
pp. 1
Author(s):  
Tosin T. Oye ◽  
Naren Gupta ◽  
Keng Goh ◽  
Toyosi K. Oye
Keyword(s):  
Air Conditioning ◽  
Indoor Environment ◽  
Respiratory Infections ◽  
Indoor Environments ◽  
Infectious Dose ◽  
Air Conditioning Systems ◽  
Droplet Nuclei ◽  
Respiratory Droplets

Substandard ventilation in restricted air-conditioning indoor places is allied with upsurge in the respiratory infections’ transmission. There have been several COVID-19 spread occurrences connected with indoor environment, together with a few from pre-symptomatic situations. Ventilation role in averting coronavirus transmission is not precise (i.e., through inhibiting transmission of an infectious dose to susceptible individuals or preventing the spreading of contagious particles to lessen the risk of transmission). SARS-CoV-2 is believed to be mainly spread through significant respiratory droplets, nevertheless, a growing amount of epidemic information associate aerosol role in the epidemics of coronavirus. Aerosols comprise of droplet nuclei and little droplets which stay in the air for longer than significant droplets. Recent studies show that coronavirus particles can stay transmissible on numerous substances, including aerosols within the indoor environments, as well as the contagion period contingent on humidity and temperature. Thus far, COVID-19 transmission via air-conditioning systems is unclear, but it is considered possible.

scholarly journals Review of Evidence of Aerosol Transmission of SARS-CoV-2 Particles

2021 ◽  
pp. 234-238
Author(s):  
Shehu Sharafadeen Aladodo ◽  
Clement Olufemi Akoshile ◽  
J. O. Otu
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Peer Review ◽  
Transmission Rate ◽  
Government Agencies ◽  
Turbulent Wind ◽  
Toilet Flushing ◽  
Mode Of Transmission ◽  
Indoor Conditions ◽  
Respiratory Droplets ◽  
Multiple Transmission

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) causes Coronavirus disease (COVID-19) through multiple transmission routes and understanding the mode of transmission is very important for its containment and prevention. Consequently, inadequate attention has been given to the spread of respiratory droplets in indoor conditions under microclimatologic turbulent wind promoted by aerosol from talking (loud), coughing, sneezing, toilet flushing of an isolation room, and resuspension of the settled virus from the surfaces. To this end, this study is presenting an early review of the process and evidence of aerosol transmission of SARS-CoV-2 particles. There are significant results of many studies including those under peer review that support aerosol and airborne transmission which government agencies should consider for reducing the transmission rate.

scholarly journals Disinfection of SARS-CoV-2 Contaminated Surfaces of Personal Items with UVC-LED Disinfection Boxes

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 598
Author(s):  
Maren Bormann ◽  
Mira Alt ◽  
Leonie Schipper ◽  
Lukas van de Sand ◽  
Mona Otte ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Close Contact ◽  
Credit Cards ◽  
Organic Matrix ◽  
Viral Loads ◽  
Small Aerosol ◽  
Time Periods ◽  
Respiratory Droplets ◽  
Glass Metal

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is transmitted from person to person by close contact, small aerosol respiratory droplets, and potentially via contact with contaminated surfaces. Herein, we investigated the effectiveness of commercial UVC-LED disinfection boxes in inactivating SARS-CoV-2-contaminated surfaces of personal items. We contaminated glass, metal, and plastic samples representing the surfaces of personal items such as smartphones, coins, or credit cards with SARS-CoV-2 formulated in an organic matrix mimicking human respiratory secretions. For disinfection, the samples were placed at different distances from UVC emitting LEDs inside commercial UVC-LED disinfection boxes and irradiated for different time periods (up to 10 min). High viral loads of SARS-CoV-2 were effectively inactivated on all surfaces after 3 min of irradiation. Even 10 s of UVC-exposure strongly reduced viral loads. Thus, UVC-LED boxes proved to be an effective method for disinfecting SARS-CoV-2-contaminated surfaces that are typically found on personal items.

scholarly journals Questioning COVID-19 Surface Stability and Fomite Spreading in Three Aeromedical Cases: A Case Series

2020 ◽  
Author(s):  
Sean Horoho ◽  
Stephen Musik ◽  
David Bryant ◽  
William Brooks ◽  
Ian M Porter
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Close Contact ◽  
Small Sample Size ◽  
Case Series ◽  
Small Sample ◽  
Posture Analysis ◽  
Surface Stability ◽  
Single Positive ◽  
Means Of Transmission ◽  
Respiratory Droplets

ABSTRACT It is well established that coronavirus disease 2019 is primarily transmitted through respiratory droplets, and there is mounting research speculation that it may also be transmitted via fomites. Several studies have shown that the virus can persist on both porous and nonporous surfaces for hours to days, depending upon the material. This article examines three cases of polymerase chain reaction–proven severe acute respiratory syndrome coronavirus 2 infection with several additional individuals meeting CDC close contact criteria. In 1 case, 195 downstream contacts were all tested to prevent a mass outbreak in a deployment posture. Analysis of these contacts yielded only a single positive test, which could be reasonably ascribed to respiratory droplet transmission. While these cases and their contacts ultimately represent a small sample size, we suggest fomite spread may not be a significant means of transmission for severe acute respiratory syndrome coronavirus 2 in real-world operational scenarios.

scholarly journals Deepening of In Silico Evaluation of SARS-CoV-2 Detection RT-qPCR Assays in the Context of New Variants

Genes ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 565
Author(s):  
Mathieu Gand ◽  
Kevin Vanneste ◽  
Isabelle Thomas ◽  
Steven Van Gucht ◽  
Arnaud Capron ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Severe Acute Respiratory Syndrome ◽  
In Silico ◽  
The Other ◽  
Viral Rna ◽  
Potential Threat ◽  
The World

For 1 year now, the world is undergoing a coronavirus disease-2019 (COVID-19) pandemic due to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The most widely used method for COVID-19 diagnosis is the detection of viral RNA by RT-qPCR with a specific set of primers and probe. It is important to frequently evaluate the performance of these tests and this can be done first by an in silico approach. Previously, we reported some mismatches between the oligonucleotides of publicly available RT-qPCR assays and SARS-CoV-2 genomes collected from GISAID and NCBI, potentially impacting proper detection of the virus. In the present study, 11 primers and probe sets investigated during the first study were evaluated again with 84,305 new SARS-CoV-2 unique genomes collected between June 2020 and January 2021. The lower inclusivity of the China CDC assay targeting the gene N has continued to decrease with new mismatches detected, whereas the other evaluated assays kept their inclusivity above 99%. Additionally, some mutations specific to new SARS-CoV-2 variants of concern were found to be located in oligonucleotide annealing sites. This might impact the strategy to be considered for future SARS-CoV-2 testing. Given the potential threat of the new variants, it is crucial to assess if they can still be correctly targeted by the primers and probes of the RT-qPCR assays. Our study highlights that considering the evolution of the virus and the emergence of new variants, an in silico (re-)evaluation should be performed on a regular basis. Ideally, this should be done for all the RT-qPCR assays employed for SARS-CoV-2 detection, including also commercial tests, although the primer and probe sequences used in these kits are rarely disclosed, which impedes independent performance evaluation.

scholarly journals An Alanine-to-Valine Substitution in the Residue 175 of Zika Virus NS2A Protein Affects Viral RNA Synthesis and Attenuates the Virus In Vivo

Viruses ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 547 ◽  
Author(s):  
Silvia Márquez-Jurado ◽  
Aitor Nogales ◽  
Ginés Ávila-Pérez ◽  
Francisco Iborra ◽  
Luis Martínez-Sobrido ◽  
...  
Keyword(s):  
Cdna Clone ◽  
Zika Virus ◽  
Rna Synthesis ◽  
Infectious Clone ◽  
Vero Cells ◽  
Viral Rna ◽  
Single Amino Acid ◽  
Reverse Genetic System ◽  
Infectious Clones

The recent outbreaks of Zika virus (ZIKV), its association with Guillain–Barré syndrome and fetal abnormalities, and the lack of approved vaccines and antivirals, highlight the importance of developing countermeasures to combat ZIKV disease. In this respect, infectious clones constitute excellent tools to accomplish these goals. However, flavivirus infectious clones are often difficult to work with due to the toxicity of some flavivirus sequences in bacteria. To bypass this problem, several alternative approaches have been applied for the generation of ZIKV clones including, among others, in vitro ligation, insertions of introns and using infectious subgenomic amplicons. Here, we report a simple and novel DNA-launched approach based on the use of a bacterial artificial chromosome (BAC) to generate a cDNA clone of Rio Grande do Norte Natal ZIKV strain. The sequence was identified from the brain tissue of an aborted fetus with microcephaly. The BAC clone was fully stable in bacteria and the infectious virus was efficiently recovered in Vero cells through direct delivery of the cDNA clone. The rescued virus yielded high titers in Vero cells and was pathogenic in a validated mouse model (A129 mice) of ZIKV infection. Furthermore, using this infectious clone we have generated a mutant ZIKV containing a single amino acid substitution (A175V) in the NS2A protein that presented reduced viral RNA synthesis in cell cultures, was highly attenuated in vivo and induced fully protection against a lethal challenge with ZIKV wild-type. This BAC approach provides a stable and reliable reverse genetic system for ZIKV that will help to identify viral determinants of virulence and facilitate the development of vaccine and therapeutic strategies.

scholarly journals Replication, pathogenicity, and transmission of SARS-CoV-2 in minks

2020 ◽  
Author(s):  
Lei Shuai ◽  
Gongxun Zhong ◽  
Quan Yuan ◽  
Zhiyuan Wen ◽  
Chong Wang ◽  
...  
Keyword(s):  
Animal Model ◽  
Severe Acute Respiratory Syndrome ◽  
Subunit Vaccine ◽  
Lung Damage ◽  
Spike Protein ◽  
Pulmonary Lesions ◽  
Potential Strategy ◽  
Respiratory Droplets

Abstract Minks are raised in many countries and have transmitted severe acute respiratory syndrome–coronavirus 2 (SARS-CoV-2) to humans. However, the biologic properties of SARS-CoV-2 in minks are largely unknown. Here, we investigated and found that SARS-CoV-2 replicates efficiently in both the upper and lower respiratory tracts, and transmits efficiently in minks via respiratory droplets; pulmonary lesions caused by SARS-CoV-2 in minks are similar to those seen in humans with COVID-19. We further found that a spike protein-based subunit vaccine largely prevented SARS-CoV-2 replication and lung damage caused by SARS-CoV-2 infection in minks. Our study indicates that minks are a useful animal model for evaluating the efficacy of drugs or vaccines against COVID-19 and that vaccination is a potential strategy to prevent minks from transmitting SARS-CoV-2.

scholarly journals Caspofungin and LTX-315 inhibit SARS-CoV-2 replication by targeting the nsp12 polymerase

2020 ◽  
Author(s):  
Min Wang ◽  
Fei Ye ◽  
Jiaqi Su ◽  
Jingru Zhao ◽  
Bin Yuan ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Vero Cells ◽  
Polymerase Activity ◽  
Structural Protein ◽  
Live Virus ◽  
Drug Candidates ◽  
Virtual Screen ◽  
Virus Assay ◽  
Promising Target

Abstract The ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, previously designated as 2019-nCoV) outbreak has caused global concern1. Currently, there are no clinically approved specific drugs or vaccines available for this virus. The viral polymerase is a promising target for developing broad- spectrum antiviral drugs. Here, based on the highly similar structure of SARS- CoV non-structural protein 12 (nsp12) polymerase subunit2, we applied virtual screen for the available compounds, including both the FDA-approved and under- clinic drugs, to identify potential antiviral molecules against SARS-CoV-2. We found two drugs, the clinically approved anti-fungi drug Caspofungin Acetate (Cancidas) and the oncolytic peptide LTX-315, can bind SARS-CoV-2 nsp12 protein to block the polymerase activity in vitro. Further live virus assay revealed that both Caspofungin Acetate and LTX-315 can effectively inhibit SARS-CoV-2 replication in vero cells. These findings present promising drug candidates for treatment of related diseases and would also stimulate the development of pan- coronavirus antiviral agents.Authors Min Wang, Fei Ye, Jiaqi Su, Jingru Zhao, and Bin Yuan contributed equally to this work.

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